1. Field of the Invention
The present invention relates to a vehicle illumination lamp employing a light-emitting element, such as a light-emitting diode, as a light source.
2. Description of Related Art
In recent years, an illumination lamp employing a light-emitting element, such as a light-emitting diode, as a light source has been developed as a vehicle illumination lamp, such as a headlamp.
In relation to the above, Japanese Patent Publication 2001-332104 discloses a vehicle illumination lamp having a first reflection surface for reflecting light from a light-emitting element, which is disposed facing a lateral direction of the lamp, rearward in relation to the lamp and a second reflection surface for reflecting in a forward direction in relation to the lamp light originated from the light-emitting element and reflected by the first reflection surface. In the vehicle illumination lamp disclosed in JP 2001-332104, the first reflection surface is formed into a spheroid with a first focal point that is at a luminous center of the light-emitting element and with a second focal point that is at a point located in a lateral direction of the first focal point; and the second reflection surface is formed into a paraboloid of revolution with a focal point that is the second focal point.
By means of employing such a vehicle illumination lamp, light illuminated from the vehicle illumination lamp can be controlled while a utilization rate of the light flux is increased in relation to light from the light-emitting element.
However, this configuration of the vehicle illumination lamp involves a problem that a light distribution pattern having a sharp cutoff line cannot be formed from light illuminated from the vehicle illumination lamp.